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root/radiance/ray/src/cv/mgflib/parser.c
Revision: 1.1
Committed: Tue Jun 21 14:45:46 1994 UTC (30 years, 4 months ago) by greg
Content type: text/plain
Branch: MAIN
Log Message:
Initial revision

File Contents

# User Rev Content
1 greg 1.1 /* Copyright (c) 1994 Regents of the University of California */
2    
3     #ifndef lint
4     static char SCCSid[] = "$SunId$ LBL";
5     #endif
6    
7     /*
8     * Parse an MGF file, converting or discarding unsupported entities
9     */
10    
11     #include <stdio.h>
12     #include <math.h>
13     #include <ctype.h>
14     #include <string.h>
15     #include "parser.h"
16     #include "lookup.h"
17     #include "messages.h"
18    
19     /*
20     * Global definitions of variables declared in parser.h
21     */
22     /* entity names */
23    
24     char mg_ename[MG_NENTITIES][MG_MAXELEN] = MG_NAMELIST;
25    
26     /* Handler routines for each entity */
27    
28     int (*mg_ehand[MG_NENTITIES])();
29    
30     /* error messages */
31    
32     char *mg_err[MG_NERRS] = MG_ERRLIST;
33    
34     MG_FCTXT *mg_file; /* current file context pointer */
35    
36     int mg_nqcdivs = MG_NQCD; /* number of divisions per quarter circle */
37    
38     /*
39     * The idea with this parser is to compensate for any missing entries in
40     * mg_ehand with alternate handlers that express these entities in terms
41     * of others that the calling program can handle.
42     *
43     * In some cases, no alternate handler is possible because the entity
44     * has no approximate equivalent. These entities are simply discarded.
45     *
46     * Certain entities are dependent on others, and mg_init() will fail
47     * if the supported entities are not consistent.
48     *
49     * Some alternate entity handlers require that earlier entities be
50     * noted in some fashion, and we therefore keep another array of
51     * parallel support handlers to assist in this effort.
52     */
53    
54     /* temporary settings for testing */
55     #define e_ies e_any_toss
56     /* alternate handler routines */
57    
58     static int e_any_toss(), /* discard unneeded entity */
59     e_ies(); /* IES luminaire file */
60     e_include(), /* include file */
61     e_sph(), /* sphere */
62     e_cyl(), /* cylinder */
63     e_cone(), /* cone */
64     e_ring(), /* ring */
65     e_torus(); /* torus */
66    
67     /* alternate handler support functions */
68    
69     static int (*e_supp[MG_NENTITIES])();
70    
71     static char FLTFMT[] = "%.12g";
72    
73     static int warpconends; /* hack for generating good normals */
74    
75    
76     void
77     mg_init() /* initialize alternate entity handlers */
78     {
79     unsigned long ineed = 0, uneed = 0;
80     register int i;
81     /* pick up slack */
82     if (mg_ehand[MG_E_IES] == NULL)
83     mg_ehand[MG_E_IES] = e_ies;
84     if (mg_ehand[MG_E_INCLUDE] == NULL)
85     mg_ehand[MG_E_INCLUDE] = e_include;
86     if (mg_ehand[MG_E_SPH] == NULL) {
87     mg_ehand[MG_E_SPH] = e_sph;
88     ineed |= 1<<MG_E_POINT|1<<MG_E_VERTEX;
89     } else
90     uneed |= 1<<MG_E_POINT|1<<MG_E_VERTEX|1<<MG_E_XF;
91     if (mg_ehand[MG_E_CYL] == NULL) {
92     mg_ehand[MG_E_CYL] = e_cyl;
93     ineed |= 1<<MG_E_POINT|1<<MG_E_VERTEX;
94     } else
95     uneed |= 1<<MG_E_POINT|1<<MG_E_VERTEX|1<<MG_E_XF;
96     if (mg_ehand[MG_E_CONE] == NULL) {
97     mg_ehand[MG_E_CONE] = e_cone;
98     ineed |= 1<<MG_E_POINT|1<<MG_E_VERTEX;
99     } else
100     uneed |= 1<<MG_E_POINT|1<<MG_E_VERTEX|1<<MG_E_XF;
101     if (mg_ehand[MG_E_RING] == NULL) {
102     mg_ehand[MG_E_RING] = e_ring;
103     ineed |= 1<<MG_E_POINT|1<<MG_E_NORMAL|1<<MG_E_VERTEX;
104     } else
105     uneed |= 1<<MG_E_POINT|1<<MG_E_NORMAL|1<<MG_E_VERTEX|1<<MG_E_XF;
106     if (mg_ehand[MG_E_TORUS] == NULL) {
107     mg_ehand[MG_E_TORUS] = e_torus;
108     ineed |= 1<<MG_E_POINT|1<<MG_E_NORMAL|1<<MG_E_VERTEX;
109     } else
110     uneed |= 1<<MG_E_POINT|1<<MG_E_NORMAL|1<<MG_E_VERTEX|1<<MG_E_XF;
111     /* check for consistency */
112     if (mg_ehand[MG_E_FACE] != NULL)
113     uneed |= 1<<MG_E_POINT|1<<MG_E_VERTEX|1<<MG_E_XF;
114     if (mg_ehand[MG_E_CXY] != NULL)
115     uneed |= 1<<MG_E_COLOR;
116     if (mg_ehand[MG_E_RD] != NULL || mg_ehand[MG_E_TD] != NULL ||
117     mg_ehand[MG_E_ED] != NULL ||
118     mg_ehand[MG_E_RS] != NULL ||
119     mg_ehand[MG_E_TS] != NULL)
120     uneed |= 1<<MG_E_MATERIAL;
121     for (i = 0; i < MG_NENTITIES; i++)
122     if (uneed & 1<<i && mg_ehand[i] == NULL) {
123     fprintf(stderr, "Missing support for \"%s\" entity\n",
124     mg_ename[i]);
125     exit(1);
126     }
127     /* add support as needed */
128     if (ineed & 1<<MG_E_VERTEX && mg_ehand[MG_E_VERTEX] != c_hvertex)
129     e_supp[MG_E_VERTEX] = c_hvertex;
130     if (ineed & 1<<MG_E_POINT && mg_ehand[MG_E_POINT] != c_hvertex)
131     e_supp[MG_E_POINT] = c_hvertex;
132     if (ineed & 1<<MG_E_NORMAL && mg_ehand[MG_E_NORMAL] != c_hvertex)
133     e_supp[MG_E_NORMAL] = c_hvertex;
134     /* discard remaining entities */
135     for (i = 0; i < MG_NENTITIES; i++)
136     if (mg_ehand[i] == NULL)
137     mg_ehand[i] = e_any_toss;
138     }
139    
140    
141    
142     int
143     mg_entity(name) /* get entity number from its name */
144     char *name;
145     {
146     static LUTAB ent_tab; /* entity lookup table */
147     register char *cp;
148    
149     if (!ent_tab.tsiz) { /* initialize hash table */
150     if (!lu_init(&ent_tab, MG_NENTITIES))
151     return(-1); /* what to do? */
152     for (cp = mg_ename[MG_NENTITIES-1]; cp >= mg_ename[0];
153     cp -= sizeof(mg_ename[0]))
154     lu_find(&ent_tab, cp)->key = cp;
155     }
156     cp = lu_find(&ent_tab, name)->key;
157     if (cp == NULL)
158     return(-1);
159     return((cp - mg_ename[0])/sizeof(mg_ename[0]));
160     }
161    
162    
163     static int
164     handle_it(en, ac, av) /* pass entity to appropriate handler */
165     register int en;
166     int ac;
167     char **av;
168     {
169     int rv;
170    
171     if (en < 0 && (en = mg_entity(av[0])) < 0)
172     return(MG_EUNK);
173     if (e_supp[en] != NULL) {
174     if ((rv = (*e_supp[en])(ac, av)) != MG_OK)
175     return(rv);
176     }
177     return((*mg_ehand[en])(ac, av));
178     }
179    
180    
181     int
182     mg_open(ctx, fn) /* open new input file */
183     register MG_FCTXT *ctx;
184     char *fn;
185     {
186     int olen;
187     register char *cp;
188    
189     ctx->lineno = 0;
190     if (fn == NULL) {
191     ctx->fname = "<stdin>";
192     ctx->fp = stdin;
193     ctx->prev = mg_file;
194     mg_file = ctx;
195     return(MG_OK);
196     }
197     /* get name relative to this context */
198     if (mg_file != NULL &&
199     (cp = strrchr(mg_file->fname, '/')) != NULL)
200     olen = cp - mg_file->fname + 1;
201     else
202     olen = 0;
203     ctx->fname = (char *)malloc(olen+strlen(fn)+1);
204     if (ctx->fname == NULL)
205     return(MG_EMEM);
206     if (olen)
207     strcpy(ctx->fname, mg_file->fname);
208     strcpy(ctx->fname+olen, fn);
209     ctx->fp = fopen(ctx->fname, "r");
210     if (ctx->fp == NULL) {
211     free((MEM_PTR)ctx->fname);
212     return(MG_ENOFILE);
213     }
214     ctx->prev = mg_file; /* establish new context */
215     mg_file = ctx;
216     return(MG_OK);
217     }
218    
219    
220     void
221     mg_close() /* close input file */
222     {
223     register MG_FCTXT *ctx = mg_file;
224    
225     mg_file = ctx->prev; /* restore enclosing context */
226     if (ctx->fp == stdin)
227     return; /* don't close standard input */
228     fclose(ctx->fp);
229     free((MEM_PTR)ctx->fname);
230     }
231    
232    
233     int
234     mg_rewind() /* rewind input file */
235     {
236     if (mg_file->lineno == 0)
237     return(MG_OK);
238     if (mg_file->fp == stdin)
239     return(MG_ESEEK); /* cannot seek on standard input */
240     if (fseek(mg_file->fp, 0L, 0) == EOF)
241     return(MG_ESEEK);
242     mg_file->lineno = 0;
243     return(MG_OK);
244     }
245    
246    
247     int
248     mg_read() /* read next line from file */
249     {
250     register int len = 0;
251    
252     do {
253     if (fgets(mg_file->inpline+len,
254     MG_MAXLINE-len, mg_file->fp) == NULL)
255     return(len);
256     mg_file->lineno++;
257     len += strlen(mg_file->inpline+len);
258     if (len > 1 && mg_file->inpline[len-2] == '\\')
259     mg_file->inpline[--len-1] = ' ';
260     } while (mg_file->inpline[len]);
261    
262     return(len);
263     }
264    
265    
266     int
267     mg_parse() /* parse current input line */
268     {
269     char abuf[MG_MAXLINE];
270     char *argv[MG_MAXARGC];
271     int en;
272     register char *cp, **ap;
273    
274     strcpy(cp=abuf, mg_file->inpline);
275     ap = argv; /* break into words */
276     for ( ; ; ) {
277     while (isspace(*cp))
278     *cp++ = '\0';
279     if (!*cp)
280     break;
281     if (ap - argv >= MG_MAXARGC-1)
282     return(MG_EARGC);
283     *ap++ = cp;
284     while (*++cp && !isspace(*cp))
285     ;
286     }
287     if (ap == argv)
288     return(MG_OK); /* no words in line */
289     *ap = NULL;
290     /* else handle it */
291     return(handle_it(-1, ap-argv, argv));
292     }
293    
294    
295     int
296     mg_load(fn) /* load an MGF file */
297     char *fn;
298     {
299     MG_FCTXT cntxt;
300     int rval;
301    
302     if ((rval = mg_open(&cntxt, fn)) != MG_OK) {
303     fprintf("%s: %s\n", fn, mg_err[rval]);
304     return(rval);
305     }
306     while (mg_read()) /* parse each line */
307     if ((rval = mg_parse()) != MG_OK) {
308     fprintf(stderr, "%s: %d: %s:\n%s", cntxt.fname,
309     cntxt.lineno, mg_err[rval],
310     cntxt.inpline);
311     break;
312     }
313     mg_close();
314     return(rval);
315     }
316    
317    
318     void
319     mg_clear() /* clear parser history */
320     {
321     c_clearall(); /* clear context tables */
322     mg_file = NULL; /* reset our context */
323     }
324    
325    
326     int
327     mg_iterate(ac, av, f) /* iterate on statement */
328     int ac;
329     register char **av;
330     int (*f)();
331     {
332     int niter, rval;
333     register int i, j;
334     char *argv[MG_MAXARGC];
335     char cntbuf[10];
336     /* build partial transformation */
337     for (i = 0; i < ac; i++) {
338     if (av[i][0] == '-' && av[i][1] == 'a' && av[i][2] == '\0')
339     break;
340     argv[i+1] = av[i];
341     }
342     argv[i+1] = NULL;
343     if (i) { /* handle transformation */
344     argv[0] = mg_ename[MG_E_XF];
345     if ((rval = handle_it(MG_E_XF, i+1, argv)) != MG_OK)
346     return(rval);
347     }
348     if (i < ac) { /* run array */
349     if (i+1 >= ac || !isint(av[i+1]))
350     return(MG_ETYPE);
351     niter = atoi(av[i+1]);
352     argv[0] = "-i";
353     argv[1] = cntbuf;
354     for (j = 2; j+i < ac; j++)
355     argv[j] = av[j+i];
356     argv[j] = NULL;
357     for (j = 0; j < niter; j++) {
358     sprintf(cntbuf, "%d", j);
359     if ((rval = mg_iterate(ac-i, argv, f)) != MG_OK)
360     return(rval);
361     }
362     } else if ((rval = (*f)()) != MG_OK) /* else do this instance */
363     return(rval);
364     if (i) { /* reset the transform */
365     argv[0] = mg_ename[MG_E_XF];
366     argv[1] = NULL;
367     (void)handle_it(MG_E_XF, 1, argv);
368     }
369     return(MG_OK);
370     }
371    
372    
373     /****************************************************************************
374     * The following routines handle unsupported entities
375     */
376    
377    
378     static int
379     e_any_toss(ac, av) /* discard an unwanted entity */
380     int ac;
381     char **av;
382     {
383     return(MG_OK);
384     }
385    
386    
387     static int
388     reload_file() /* reload current MGF file */
389     {
390     register int rval;
391    
392     if ((rval = mg_rewind()) != MG_OK)
393     return(rval);
394     while (mg_read())
395     if ((rval = mg_parse()) != MG_OK)
396     return(rval);
397     return(MG_OK);
398     }
399    
400    
401     static int
402     e_include(ac, av) /* include file */
403     int ac;
404     char **av;
405     {
406     MG_FCTXT ictx;
407     int rv;
408    
409     if (ac < 2)
410     return(MG_EARGC);
411     if ((rv = mg_open(&ictx, av[1])) != MG_OK)
412     return(rv);
413     if ((rv = mg_iterate(ac-2, av+2, reload_file)) != MG_OK) {
414     fprintf(stderr, "%s: %d: %s:\n%s", ictx.fname,
415     ictx.lineno, mg_err[rv], ictx.inpline);
416     mg_close();
417     return(MG_EINCL);
418     }
419     mg_close();
420     return(MG_OK);
421     }
422    
423    
424     static void
425     make_axes(u, v, w) /* compute u and v given w (normalized) */
426     FVECT u, v, w;
427     {
428     register int i;
429    
430     v[0] = v[1] = v[2] = 0.;
431     for (i = 0; i < 3; i++)
432     if (w[i] < .6 && w[i] > -.6)
433     break;
434     v[i] = 1.;
435     fcross(u, v, w);
436     normalize(u);
437     fcross(v, w, u);
438     }
439    
440    
441     static int
442     e_sph(ac, av) /* expand a sphere into cones */
443     int ac;
444     char **av;
445     {
446     static char p2x[24], p2y[24], p2z[24], r1[24], r2[24];
447     static char *v1ent[5] = {mg_ename[MG_E_VERTEX],"_sv1","=","_sv2"};
448     static char *v2ent[4] = {mg_ename[MG_E_VERTEX],"_sv2","="};
449     static char *p2ent[5] = {mg_ename[MG_E_POINT],p2x,p2y,p2z};
450     static char *conent[6] = {mg_ename[MG_E_CONE],"_sv1",r1,"_sv2",r2};
451     register C_VERTEX *cv;
452     register int i;
453     int rval;
454     double rad;
455     double theta;
456    
457     if (ac != 3)
458     return(MG_EARGC);
459     if ((cv = c_getvert(av[1])) == NULL)
460     return(MG_EUNDEF);
461     if (!isflt(av[2]))
462     return(MG_ETYPE);
463     rad = atof(av[2]);
464     /* initialize */
465     warpconends = 1;
466     if ((rval = handle_it(MG_E_VERTEX, 3, v2ent)) != MG_OK)
467     return(rval);
468     sprintf(p2x, FLTFMT, cv->p[0]);
469     sprintf(p2y, FLTFMT, cv->p[1]);
470     sprintf(p2z, FLTFMT, cv->p[2]+rad);
471     if ((rval = handle_it(MG_E_POINT, 4, p2ent)) != MG_OK)
472     return(rval);
473     r2[0] = '0'; r2[1] = '\0';
474     for (i = 1; i <= 2*mg_nqcdivs; i++) {
475     theta = i*(PI/2)/mg_nqcdivs;
476     if ((rval = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
477     return(rval);
478     sprintf(p2z, FLTFMT, cv->p[2]+rad*cos(theta));
479     if ((rval = handle_it(MG_E_VERTEX, 2, v2ent)) != MG_OK)
480     return(rval);
481     if ((rval = handle_it(MG_E_POINT, 4, p2ent)) != MG_OK)
482     return(rval);
483     strcpy(r1, r2);
484     sprintf(r2, FLTFMT, rad*sin(theta));
485     if ((rval = handle_it(MG_E_CONE, 5, conent)) != MG_OK)
486     return(rval);
487     }
488     warpconends = 0;
489     return(MG_OK);
490     }
491    
492    
493     static int
494     e_torus(ac, av) /* expand a torus into cones */
495     int ac;
496     char **av;
497     {
498     static char p2[3][24], r1[24], r2[24];
499     static char *v1ent[5] = {mg_ename[MG_E_VERTEX],"_tv1","=","_tv2"};
500     static char *v2ent[5] = {mg_ename[MG_E_VERTEX],"_tv2","="};
501     static char *p2ent[5] = {mg_ename[MG_E_POINT],p2[0],p2[1],p2[2]};
502     static char *conent[6] = {mg_ename[MG_E_CONE],"_tv1",r1,"_tv2",r2};
503     register C_VERTEX *cv;
504     register int i, j;
505     int rval;
506     int sgn;
507     double minrad, maxrad, avgrad;
508     double theta;
509    
510     if (ac != 4)
511     return(MG_EARGC);
512     if ((cv = c_getvert(av[1])) == NULL)
513     return(MG_EUNDEF);
514     if (cv->n[0]==0. && cv->n[1]==0. && cv->n[2]==0.)
515     return(MG_EILL);
516     if (!isflt(av[2]) || !isflt(av[3]))
517     return(MG_ETYPE);
518     minrad = atof(av[2]);
519     maxrad = atof(av[3]);
520     /* check orientation */
521     if (minrad > 0.)
522     sgn = 1;
523     else if (minrad < 0.)
524     sgn = -1;
525     else if (maxrad > 0.)
526     sgn = 1;
527     else if (maxrad < 0.)
528     sgn = -1;
529     else
530     return(MG_EILL);
531     if (sgn*(maxrad-minrad) <= 0.)
532     return(MG_EILL);
533     /* initialize */
534     warpconends = 1;
535     v2ent[3] = av[1];
536     for (j = 0; j < 3; j++)
537     sprintf(p2[j], FLTFMT, cv->p[j] +
538     .5*sgn*(maxrad-minrad)*cv->n[j]);
539     if ((rval = handle_it(MG_E_VERTEX, 4, v2ent)) != MG_OK)
540     return(rval);
541     if ((rval = handle_it(MG_E_POINT, 4, p2ent)) != MG_OK)
542     return(rval);
543     sprintf(r2, FLTFMT, avgrad=.5*(minrad+maxrad));
544     /* run outer section */
545     for (i = 1; i <= 2*mg_nqcdivs; i++) {
546     theta = i*(PI/2)/mg_nqcdivs;
547     if ((rval = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
548     return(rval);
549     for (j = 0; j < 3; j++)
550     sprintf(p2[j], FLTFMT, cv->p[j] +
551     .5*sgn*(maxrad-minrad)*cos(theta)*cv->n[j]);
552     if ((rval = handle_it(MG_E_VERTEX, 2, v2ent)) != MG_OK)
553     return(rval);
554     if ((rval = handle_it(MG_E_POINT, 4, p2ent)) != MG_OK)
555     return(rval);
556     strcpy(r1, r2);
557     sprintf(r2, FLTFMT, avgrad + .5*(maxrad-minrad)*sin(theta));
558     if ((rval = handle_it(MG_E_CONE, 5, conent)) != MG_OK)
559     return(rval);
560     }
561     /* run inner section */
562     sprintf(r2, FLTFMT, -.5*(minrad+maxrad));
563     for ( ; i <= 4*mg_nqcdivs; i++) {
564     theta = i*(PI/2)/mg_nqcdivs;
565     for (j = 0; j < 3; j++)
566     sprintf(p2[j], FLTFMT, cv->p[j] +
567     .5*sgn*(maxrad-minrad)*cos(theta)*cv->n[j]);
568     if ((rval = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
569     return(rval);
570     if ((rval = handle_it(MG_E_VERTEX, 2, v2ent)) != MG_OK)
571     return(rval);
572     if ((rval = handle_it(MG_E_POINT, 4, p2ent)) != MG_OK)
573     return(rval);
574     strcpy(r1, r2);
575     sprintf(r2, FLTFMT, -avgrad - .5*(maxrad-minrad)*sin(theta));
576     if ((rval = handle_it(MG_E_CONE, 5, conent)) != MG_OK)
577     return(rval);
578     }
579     warpconends = 0;
580     return(MG_OK);
581     }
582    
583    
584     static int
585     e_cyl(ac, av) /* replace a cylinder with equivalent cone */
586     int ac;
587     char **av;
588     {
589     static char *avnew[6] = {mg_ename[MG_E_CONE]};
590    
591     if (ac != 4)
592     return(MG_EARGC);
593     avnew[1] = av[1];
594     avnew[2] = av[2];
595     avnew[3] = av[3];
596     avnew[4] = av[2];
597     return(handle_it(MG_E_CONE, 5, avnew));
598     }
599    
600    
601     static int
602     e_ring(ac, av) /* turn a ring into polygons */
603     int ac;
604     char **av;
605     {
606     static char p3[3][24], p4[3][24];
607     static char *nzent[5] = {mg_ename[MG_E_NORMAL],"0","0","0"};
608     static char *v1ent[5] = {mg_ename[MG_E_VERTEX],"_rv1","="};
609     static char *v2ent[5] = {mg_ename[MG_E_VERTEX],"_rv2","=","_rv3"};
610     static char *v3ent[4] = {mg_ename[MG_E_VERTEX],"_rv3","="};
611     static char *p3ent[5] = {mg_ename[MG_E_POINT],p3[0],p3[1],p3[2]};
612     static char *v4ent[4] = {mg_ename[MG_E_VERTEX],"_rv4","="};
613     static char *p4ent[5] = {mg_ename[MG_E_POINT],p4[0],p4[1],p4[2]};
614     static char *fent[6] = {mg_ename[MG_E_FACE],"_rv1","_rv2","_rv3","_rv4"};
615     register C_VERTEX *cv;
616     register int i, j;
617     FVECT u, v;
618     double minrad, maxrad;
619     int rv;
620     double theta, d;
621    
622     if (ac != 4)
623     return(MG_EARGC);
624     if ((cv = c_getvert(av[1])) == NULL)
625     return(MG_EUNDEF);
626     if (cv->n[0]==0. && cv->n[1]==0. && cv->n[2]==0.)
627     return(MG_EILL);
628     if (!isflt(av[2]) || !isflt(av[3]))
629     return(MG_ETYPE);
630     minrad = atof(av[2]);
631     maxrad = atof(av[3]);
632     if (minrad < 0. || maxrad <= minrad)
633     return(MG_EILL);
634     /* initialize */
635     make_axes(u, v, cv->n);
636     for (j = 0; j < 3; j++)
637     sprintf(p3[j], FLTFMT, cv->p[j] + maxrad*u[j]);
638     if ((rv = handle_it(MG_E_VERTEX, 3, v3ent)) != MG_OK)
639     return(rv);
640     if ((rv = handle_it(MG_E_POINT, 4, p3ent)) != MG_OK)
641     return(rv);
642     if (minrad == 0.) { /* closed */
643     v1ent[3] = av[1];
644     if ((rv = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
645     return(rv);
646     if ((rv = handle_it(MG_E_NORMAL, 4, nzent)) != MG_OK)
647     return(rv);
648     for (i = 1; i <= 4*mg_nqcdivs; i++) {
649     theta = i*(PI/2)/mg_nqcdivs;
650     if ((rv = handle_it(MG_E_VERTEX, 4, v2ent)) != MG_OK)
651     return(rv);
652     for (j = 0; j < 3; j++)
653     sprintf(p3[j], FLTFMT, cv->p[j] +
654     maxrad*u[j]*cos(theta) +
655     maxrad*v[j]*sin(theta));
656     if ((rv = handle_it(MG_E_VERTEX, 3, v3ent)) != MG_OK)
657     return(rv);
658     if ((rv = handle_it(MG_E_POINT, 4, p3ent)) != MG_OK)
659     return(rv);
660     if ((rv = handle_it(MG_E_FACE, 4, fent)) != MG_OK)
661     return(rv);
662     }
663     } else { /* open */
664     if ((rv = handle_it(MG_E_VERTEX, 3, v4ent)) != MG_OK)
665     return(rv);
666     for (j = 0; j < 3; j++)
667     sprintf(p4[j], FLTFMT, cv->p[j] + minrad*u[j]);
668     if ((rv = handle_it(MG_E_POINT, 4, p4ent)) != MG_OK)
669     return(rv);
670     v1ent[3] = "_rv4";
671     for (i = 1; i <= 4*mg_nqcdivs; i++) {
672     theta = i*(PI/2)/mg_nqcdivs;
673     if ((rv = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
674     return(rv);
675     if ((rv = handle_it(MG_E_VERTEX, 4, v2ent)) != MG_OK)
676     return(rv);
677     for (j = 0; j < 3; j++) {
678     d = u[j]*cos(theta) + v[j]*sin(theta);
679     sprintf(p3[j], FLTFMT, cv->p[j] + maxrad*d);
680     sprintf(p4[j], FLTFMT, cv->p[j] + minrad*d);
681     }
682     if ((rv = handle_it(MG_E_VERTEX, 3, v3ent)) != MG_OK)
683     return(rv);
684     if ((rv = handle_it(MG_E_POINT, 4, p3ent)) != MG_OK)
685     return(rv);
686     if ((rv = handle_it(MG_E_VERTEX, 3, v4ent)) != MG_OK)
687     return(rv);
688     if ((rv = handle_it(MG_E_POINT, 4, p4ent)) != MG_OK)
689     return(rv);
690     if ((rv = handle_it(MG_E_FACE, 5, fent)) != MG_OK)
691     return(rv);
692     }
693     }
694     return(MG_OK);
695     }
696    
697    
698     static int
699     e_cone(ac, av) /* turn a cone into polygons */
700     int ac;
701     char **av;
702     {
703     static char p3[3][24], p4[3][24], n3[3][24], n4[3][24];
704     static char *v1ent[5] = {mg_ename[MG_E_VERTEX],"_cv1","="};
705     static char *v2ent[5] = {mg_ename[MG_E_VERTEX],"_cv2","=","_cv3"};
706     static char *v3ent[4] = {mg_ename[MG_E_VERTEX],"_cv3","="};
707     static char *p3ent[5] = {mg_ename[MG_E_POINT],p3[0],p3[1],p3[2]};
708     static char *n3ent[5] = {mg_ename[MG_E_NORMAL],n3[0],n3[1],n3[2]};
709     static char *v4ent[4] = {mg_ename[MG_E_VERTEX],"_cv4","="};
710     static char *p4ent[5] = {mg_ename[MG_E_POINT],p4[0],p4[1],p4[2]};
711     static char *n4ent[5] = {mg_ename[MG_E_NORMAL],n4[0],n4[1],n4[2]};
712     static char *fent[6] = {mg_ename[MG_E_FACE],"_cv1","_cv2","_cv3","_cv4"};
713     register C_VERTEX *cv1, *cv2;
714     register int i, j;
715     FVECT u, v, w;
716     double rad1, rad2;
717     int sgn;
718     double n1off, n2off;
719     double d;
720     int rv;
721     double theta;
722    
723     if (ac != 5)
724     return(MG_EARGC);
725     if ((cv1 = c_getvert(av[1])) == NULL ||
726     (cv2 = c_getvert(av[3])) == NULL)
727     return(MG_EUNDEF);
728     if (!isflt(av[2]) || !isflt(av[4]))
729     return(MG_ETYPE);
730     rad1 = atof(av[2]);
731     rad2 = atof(av[4]);
732     if (rad1 == 0.) {
733     if (rad2 == 0.)
734     return(MG_EILL);
735     } else if (rad2 != 0.) {
736     if (rad1 < 0. ^ rad2 < 0.)
737     return(MG_EILL);
738     } else { /* swap */
739     C_VERTEX *cv;
740    
741     cv = cv1;
742     cv1 = cv2;
743     cv2 = cv;
744     d = rad1;
745     rad1 = rad2;
746     rad2 = d;
747     }
748     sgn = rad2 < 0. ? -1 : 1;
749     /* initialize */
750     for (j = 0; j < 3; j++)
751     w[j] = cv1->p[j] - cv2->p[j];
752     if ((d = normalize(w)) == 0.)
753     return(MG_EILL);
754     n1off = n2off = (rad2 - rad1)/d;
755     if (warpconends) /* hack for e_sph and e_torus */
756     n2off = tan(atan(n2off)-(PI/4)/mg_nqcdivs);
757     n2off = sgn*n2off;
758     make_axes(u, v, w);
759     for (j = 0; j < 3; j++) {
760     sprintf(p3[j], FLTFMT, cv2->p[j] + rad2*u[j]);
761     sprintf(n3[j], FLTFMT, u[j] + w[j]*n2off);
762     }
763     if ((rv = handle_it(MG_E_VERTEX, 3, v3ent)) != MG_OK)
764     return(rv);
765     if ((rv = handle_it(MG_E_POINT, 4, p3ent)) != MG_OK)
766     return(rv);
767     if ((rv = handle_it(MG_E_NORMAL, 4, n3ent)) != MG_OK)
768     return(rv);
769     if (rad1 == 0.) { /* triangles */
770     v1ent[3] = av[1];
771     if ((rv = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
772     return(rv);
773     for (j = 0; j < 3; j++)
774     sprintf(n4[j], FLTFMT, w[j]);
775     if ((rv = handle_it(MG_E_NORMAL, 4, n4ent)) != MG_OK)
776     return(rv);
777     for (i = 1; i <= 4*mg_nqcdivs; i++) {
778     theta = sgn*i*(PI/2)/mg_nqcdivs;
779     if ((rv = handle_it(MG_E_VERTEX, 4, v2ent)) != MG_OK)
780     return(rv);
781     for (j = 0; j < 3; j++) {
782     d = u[j]*cos(theta) + v[j]*sin(theta);
783     sprintf(p3[j], FLTFMT, cv2->p[j] + rad2*d);
784     sprintf(n3[j], FLTFMT, d + w[j]*n2off);
785     }
786     if ((rv = handle_it(MG_E_VERTEX, 3, v3ent)) != MG_OK)
787     return(rv);
788     if ((rv = handle_it(MG_E_POINT, 4, p3ent)) != MG_OK)
789     return(rv);
790     if ((rv = handle_it(MG_E_NORMAL, 4, n3ent)) != MG_OK)
791     return(rv);
792     if ((rv = handle_it(MG_E_FACE, 4, fent)) != MG_OK)
793     return(rv);
794     }
795     } else { /* quads */
796     v1ent[3] = "_cv4";
797     if (warpconends) /* hack for e_sph and e_torus */
798     n1off = tan(atan(n1off)+(PI/4)/mg_nqcdivs);
799     n1off = sgn*n1off;
800     for (j = 0; j < 3; j++) {
801     sprintf(p4[j], FLTFMT, cv1->p[j] + rad1*u[j]);
802     sprintf(n4[j], FLTFMT, u[j] + w[j]*n1off);
803     }
804     if ((rv = handle_it(MG_E_VERTEX, 3, v4ent)) != MG_OK)
805     return(rv);
806     if ((rv = handle_it(MG_E_POINT, 4, p4ent)) != MG_OK)
807     return(rv);
808     if ((rv = handle_it(MG_E_NORMAL, 4, n4ent)) != MG_OK)
809     return(rv);
810     for (i = 1; i <= 4*mg_nqcdivs; i++) {
811     theta = sgn*i*(PI/2)/mg_nqcdivs;
812     if ((rv = handle_it(MG_E_VERTEX, 4, v1ent)) != MG_OK)
813     return(rv);
814     if ((rv = handle_it(MG_E_VERTEX, 4, v2ent)) != MG_OK)
815     return(rv);
816     for (j = 0; j < 3; j++) {
817     d = u[j]*cos(theta) + v[j]*sin(theta);
818     sprintf(p3[j], FLTFMT, cv2->p[j] + rad2*d);
819     sprintf(n3[j], FLTFMT, d + w[j]*n2off);
820     sprintf(p4[j], FLTFMT, cv1->p[j] + rad1*d);
821     sprintf(n4[j], FLTFMT, d + w[j]*n1off);
822     }
823     if ((rv = handle_it(MG_E_VERTEX, 3, v3ent)) != MG_OK)
824     return(rv);
825     if ((rv = handle_it(MG_E_POINT, 4, p3ent)) != MG_OK)
826     return(rv);
827     if ((rv = handle_it(MG_E_NORMAL, 4, n3ent)) != MG_OK)
828     return(rv);
829     if ((rv = handle_it(MG_E_VERTEX, 3, v4ent)) != MG_OK)
830     return(rv);
831     if ((rv = handle_it(MG_E_POINT, 4, p4ent)) != MG_OK)
832     return(rv);
833     if ((rv = handle_it(MG_E_NORMAL, 4, n4ent)) != MG_OK)
834     return(rv);
835     if ((rv = handle_it(MG_E_FACE, 5, fent)) != MG_OK)
836     return(rv);
837     }
838     }
839     return(MG_OK);
840     }